We’re in the Limelight (and the emission lines are incredible!)

Scientific Disciplines — Physics and Chemistry (Spectroscopy)

Every element in nature has a characteristic emission spectrum consisting of bright lines of light unique to that element. These beautiful spectral lines can be observed only when the element is electronically excited, which requires the expenditure of considerable energy. Over a century ago, lime used to be heated to incandescence to provide stage lighting (“limelight”) for actors. The birthday child and his or her friends will build and take home their very own spectroscope enabling them to view the emission spectra of among other things, sunlight (hydrogen and helium emission) and fluorescent lighting (mercury emission), and yes, even limelight. The participants will analyze the light emitted by excited Noble gases (formerly called “inert gases”) in high voltage discharge tubes. They’ll also see how scientists use both atomic emission and atomic absorption spectra to provide chemical information about the composition of distant celestial bodies and for direct analysis of unknown elemental mixtures here on earth.